Sex differences in adult laboratory (lab) and clinical pain prompted our original study of lab pain in 244 healthy children (8-17 years) to identify salient child factors underlying emerging sex differences found during adolescence in clinical pain patients. We examined puberty, sex, and psychological vulnerability and found some positive but inconsistent main effects and interactions in different pain response domains. Tolerance was greater for boys than girls in the pressure task and, controlling for age, cold pressor and pressure tolerance were greater for the late pubertal samples. Also, for cold and thermal tasks, boys increased their tolerance more than girls with increasing age, controlling for puberty. A derived variable, psychological vulnerability, was the strongest predictor of lab pain and was found to be a partial mediator between puberty and pain intensity. No highly salient sex or pubertal differences in children's pain, in or out of the lab, were found that could help explain sex differences seen in adult populations. Findings from our limited set of parent variables suggest that parent characteristics may be more potent than child factors in predicting children's pain. These key findings lead us, for this competing continuation study, to turn our attention to the inter-relationships between biopsychosocial maternal and paternal factors, child sex, pubertal status, and child chronic pain condition as predictors of children's lab and non-lab pain. We will study 240 children (8-17 yrs, 50 percent females, 50 percent late puberty, 50 percent with chronic headaches) and their mothers to assess non-lab pain history, pain-related disability, total bodily symptoms, negative affectivity, pain catastrophizing, gender-related expectations about pain, and parents'responses to children's pain. All mothers, children, and a subset of 50 fathers will individually undergo four lab pain tasks (cold, heat, pressure tolerance, and pressure pain sensitivity). Physiological, self-report, and behavioral lab pain responses will be assessed. All fathers will complete the questionnaires. The parent/child pain relationship offers a unique context within which to study critical components of the biopsychosocial pain model and the roles of sex and puberty. Our competing continuation study will advance our understanding of sex differences in pain, help identify children at risk by virtue of their pubertal status, sex, and parental influences, expand our knowledge of sex-related pain predictors, and provide pathways for intervention.